In the automotive field, it is commonplace to provide a radiator fan, to increase radiator cooling airflow, and it is traditional to secure such fan to the chassis or bodywork of the vehicle. It is also known to secure accessories such as radiator fans directly to radiators. For example, it is known to substitute, for each of one or more of the tubes of a heat exchanger, a mounting plate having at least one integral fastening lug projecting from a side edge, and to which the accessory is attached. This arrangement provides a relatively robust, inexpensive mount for the accessory. However, the substitution of mounting plates for tubes, all things remaining equal, tends to decrease heat exchange performance.